I have a few concerns about my two female Black Mollies I have in my 135 litre tank, I’ve been treating them for white spot and so have been keeping them both in a mini 12 litre quarantine tank for a week. I have just put them back in the main tank this morning. While they were in the small tank the one with the least number of spot had become quite aggressive towards the other one with a more severe case. I tried moving the minimal decor I had in there around to try and disorientated her but she still kept nipping, poking and chasing. I thought that it was because they were in a much smaller tank than they had previously been in so they were a bit confined. When I put them back into the main tank a HUGE fight broke out between them and they were nipping and chasing eachother, smacking eachother around the tank and onto the glass. I don’t know how to stop the aggression and I can’t put on of them back in the quarantine tank as there is a different Dalmation Molly in there who is about to give birth! What do I do about the Black Mollies. I don’t want them to end up severely hurting eachother or even killing eachother!!